The idea that fundamental physics involves causal order but not strong causation may raise some concerns amongst the subset of scientific realists who argue that realism is necessarily requires causal explanation[1]}, [2]}. This kind of position seems to be related to the common idea that there is a contrast between (bare) correlation and causation, as epitomized by the slogan `correlation is not causation,' which comes with the implication that `causation' expresses something stronger than bare correlation. And indeed, if `(strong) causation' and `bare correlation' were our only options for describing the character of fundamental physics, it would seem reasonable to say that the realist must be committed to a causal description, since committing only to `bare correlations' would lead to a collapse into constructive empiricism[3]}. However, (strong) causation and bare correlations are not in fact the only possible options. In particular, we would argue that causation is stronger than correlation not because it is asymmetric (after all, bare correlations themselves can also be asymmetric) but because it is modal. It is precisely this modal force which is captured in the interventionist account of the difference between causation and correlation - `only some and not all correlational relationships are potentially exploitable for purposes of manipulation and control; we regard those relationships that are so exploitable as causal,'[4]} - since modal relations are required to ground counterfactuals describing what would be the outcome of various kinds of manipulation and control. So we can still give a realist account of fundamental physics without invoking strong causation, provided that we are willing to make some other kind of modal claim, for example by postulating symmetric modal relations.
